Separate eggs. Beat the egg whites and 2 tablespoons of water until stiff, adding 50 g sugar and vanillin sugar. Beat the egg yolks one after the other. Mix flour, starch and baking powder, sieve onto the egg foam and fold in. Line the bottom of a springform pan (22 cm Ø) with baking paper. Fill in the sponge cake mixture and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 20 minutes.
Let them cool down. Remove baking paper. Cut the sponge cake once horizontally and place a springform pan rim or cake ring around the bottom. Soak gelatine in cold water. Mix mascarpone, yoghurt and 2 tablespoons of sugar. Squeeze the gelatine, dissolve it and mix with 2 tablespoons of mascarpone cream. Stir into the remaining cream. Coarsely chop the truffles. Whip 100 g cream until stiff. Fold truffles and cream into the cream. Spread the cream on the bottom cake layer and smooth it down. Place the upper cake layer on top. Chill for at least 4 hours.
Stir into the remaining cream. Coarsely chop the truffles. Whip 100 g cream until stiff. Fold truffles and cream into the cream. Spread the cream on the bottom cake layer and smooth it down. Place the upper cake layer on top. Chill for at least 4 hours. For the decoration, chop the chocolate and melt over a warm water bath. Spread very thinly on a large piece of baking paper and leave to set in the fridge. Remove the cake from the edge of the mould with a knife. Whip 150 g cream until stiff and spread the cake all around. Sort the raspberries and cover the cake with them. Break the chocolate coating into pieces and press them onto the edge of the cake
For the decoration, chop the chocolate and melt over a warm water bath. Spread very thinly on a large piece of baking paper and leave to set in the fridge. Remove the cake from the edge of the mould with a knife. Whip 150 g cream until stiff and spread the cake all around. Sort the raspberries and cover the cake with them. Break the chocolate coating into pieces and press them onto the edge of the cake
4 hours 20 minutes waiting time